Kiln



Filed Sept. 7, 1929 3 Sheets-Sheet l IHH'LL Aug. 30, 1932.

H. M. ROBERTSON- KILN Filed Sept. 7. 1929 3 Sheets-Sheet 3 Patented Aug. 30, 1 932 UNITED STATES HARRY H. ROBERTSON, OF CLEVELAND, OHIO KILN Application filed September This invention relates to a kiln of the continuous type.

One object of the invention is to provide an improved kiln having a primary heating 6 chamber or zone and a source of heat therefor so constructed and arranged that heat is applied above and below the ware support to insure efficient and more uniform burning of the ware and less waste thereof due to 1 over-burning or under-burning.

Another object of the invention is to provide an improved continuous kiln through which the ware, disposed on overhanging supports, is conveyed and in which the heating means comprise electric heating units so arranged that heat is supplied both below and above the overhanging portions of the ware supports. 2

Another object of the invention is to provide an improved continuous kiln having a primary heating chamber the side and top walls of which are arranged and correlated to insure a more uniform circulation and distribution of the heat, both the heat sup- 2 plied by the heating means and the heat radiating from the walls of the chamber, upon and through the ware, whereby'less waste due to over-burning and under-burning of the ware results.

Other objects of the invention will be apparent to those skilled in the art to which my invention relates from the following description taken in connection with the accompanying drawings, wherein Figs. 1 and 2 taken together constitute a longitudinal section on the line 1-1 of Fi 3 of a kiln embodying my invention.

Fig. 3 is a fragmentary section on the line 33 of Figs. 1 and t enlarged.

Fig. 4 is a fragmentary section on the line 11 of Fig. 3, enlarged, the ware conveyors being omitted.

Fig. 5 is fragmentary section on the line 55 of Fig. 3.

In the drawings, 1 indicates as an entirety a structure having a secondary or preliminary heating chamber or zone 2, a primary heating chamber or Zone 2, an annealing chamber 3 and a cooling chamber or zone 4 50 disposed in connected end to end relation and 7, 1929. Serial No. 381,024.

forming a continuous kiln through wh'ch ware supports 5 move. these supports being mounted on wheeled conveyors or trucks 6 adapted to travel on suitable tracks 7. As shown, the tracks 7 are below the structure 1 and the trucks 6 have pordons 8 extending upwardly through an opening 1a formed in and extending throughout the length of the bottom 16 of the structure 1 to mount the sup ports 5 above or in spaced relation to the lower portion of the chambers 2, 2, 3 and 4 for movement therethrough. This form of construction forms the subject-matter of my co-pcnding' application Ser. No. 320,175; for which reason claims to the broader aspects of the invention are made in said application; whereas this application relates to certain improvements in the construction shown in myaforesaid application and is therefore a continuation in part thereof.

The supports 5 are not shown in detail as the same may be and are preferably constructed substantially according to the supports described and claimed in my co-pending application Ser. No. 357,742 which has become Patent 1,832,818, for which reason no claim to the supports is made herein, except in connection with the improvements herein disclosed.

The heating chamber 2 comprises downwardly inclined side walls 9 terminating at spaced points below the overhanging or cantilever portions of the supports 5, to form the longitudinal opening 1a, already referred to, and an arch 10 extending between the upper ends of the side walls 9. Each of these walls consists of an inner section of suitable refractory material 11 and an outer section of suitable insulating material 12. The inner sections 11 of the side walls 9 rest on longitudinal sills 13, also formed of suitable refractory material. The lower face of each sill 13 is provided with a. shoulder 14 which engages a complementary wall on a base member 15 and the base member is seated against the vertical flange 16 of an angle 17 anchored, as will later appear. here the tracks 7 are to be substantially on the level of the surface, the structure 1 is supported by a frame work 18 consisting of spaced I-beams 19 resting on the floorin 20 oairs of outer u ri hts 21 o a l a mounted on the beams 19, pairs of inner uprights 22 also mounted on the beamslt) and supporting-sills 22a and I-bea-ms 2056 connected in any desired manner at their outer endsvto th uprights 1 and resting on their inner portions on the sills 22a. The various elements of the frame-work 18 may be se- 7 cured to each other in any well known manner. The upper ends of the uprights 21 are preferably connected tie-rods '24 m dicates a sheath for the slde walls 9. This sheath ng preferably comprises steel platesarranged edge to edge and having Vertical portion 242a engaging theuprights 21 an inclinedportion 2 1) and a horizontal portion 240mm on the beams 20a. The horizontal flanges, or the angles 17 are suitable secured to the free edges of the portions 240. As shown the insulating material extends over the horizontal portion 2&0 of the sheathing and below the base member 15. The sheathing 24 serves as a support for the materials when the walls are being construct-ed and also protects these walls to prevent their deterioration; Each of the verticalportions era has secured to its inner surface an angle 25, 4:

which forms a seat for the outer sides o blocks 26 extending from end to end of the heating chamber the inner sides of the blocks resting on the upper end of the wall face are in spaced relation and disposed above and below and overlap. a longitudinally extending r b 29project1ng outwardly from the adjacent face of each truck portion 8, these correlated ribs serving to prevent the escape of heat an-dintake of air with resulting loss of heating eliiciency.

The walls forming the chambers 2 and 3 are preferably constructed in a similar manher to the main heating chamber 2', as above described, except that the insulating walls for the annealing chamber 3 may be om tted, if desired. chamber is connected with an elongated supply chamber. 30 preferably similar in construction to the chambers 2 2 and 3, except that its roof 31 is preferably horizontal so as to be in relatively close relation to the load on the supports 5, thereby preventing inflow of air into the preheating chamber.

32 indicates a damper controlled, exhaust flue leadmg'through the roof or arch 10 for the opening 164 7 At its outer end the preheating the preheating chamber, this flue being disheated to a relatively high temperature before entering the chamber 3.

The cooling chamber ll. is connected in end to end relation to the outer end of the annealing chamber 3 as already setforth. The roof for the chamber a preferably consists of a manifold 33 extending from end to end thereof. The manifold has at its outer end an inlet opening 33a connected to a conduit 34 through which air flows to the manifold.

The inner. end of the manifold hasan outlet 335 connected to a discharge conduit 3 5.

The conduit 35 is provided with a power driven suction fan whichinduces ahow of air" through the manifold 33. Thebottom wall of the manifold is preferably horizontal and disposed in close parallel relation to the ware on thesupports 5 as the latter moves to the discharge opening; v V

37 indicates as an entirety the heat supply means for the chamber 2. The means 37 comprise pairs of electric heating elements 38,3805, disposed along eachwall 9 and supported in parallelrelation thereto and a connector 39 between the elements of each pair to connect them in series. The elements com prise rods of suitable resistance material and each connector 39 consists of a plate of con ductingmaterial countersunk in an un stand ing portion 13a of the blocks 13 As shown each plate 39 is formed with a pairof recesses which receive the lower ends of a pair of rods 38, 38a. The upper ends ofthe rods fit into collars 4O preferably'formed of suitable insulating material.

The collars 40 are countersunlrin the key:

jacent support 2a in any desired mariner,

Each angle is formed with an opening in wlnchis mounted a bolt 45 GXlIQIlCllD through D V a? the bifurcations of the ad acent arm 43.

' Provided on each bolt i5 is awasher 4-6 and a nut '(such as a thumb nut) 47. Between the washer 46 and arm 43 and coiled around the bolt is a spring 48, these parts being so arranged and related that upon tightening of the nut 47, the spring 48 acting through the arm 43 will maintain the adjacent conductor 42 in yielding contact with the adjacent element 38 or 38a. The mounting for each conductor is provided with a threaded shank 49 carrying two nuts 50 between which one end of a lead 51 is clamped, the other end of the lead being connected to one supply main 52. As shown in Fig. 5, one element 38 is connected to one main 52 and the other element 38a is connected to the other main 52, so that each pair of elements and its connector 39 forms a complete circuit.

Suitable switch means are provided for controlling the supply of current through the mains 52. The mains may be carried through a pipe 53 of insulating material, mounted on an angle 54, which is supported by the uprights 21.

In my construction of kiln it will be noted that the resistance elements are supported close to and in parallel relation to the side walls 9. This arrangement permits the inner sections of the walls to absorb heat, which is radiated therefrom. As these side walls are inclined upwardly the radiant heat is projected upwardly into the space below the arch 10 and as the latter is curved in symmetrical relation to the moving ware, the heat radiating from the latter is directed downwardly thereupon to effect its burning. By this arrangement of walls, the heat resulting from the resistance rods or elements circulates and radiates into the space substantially centrally of the walls 9, 9, 10, so that a large volume of air heated to the desired temperature is provided in the chamber 2 and serves to effect burning of the ware in an economical manner.

The trucks 6 are moved step by step by means of a thrust member 54 which is reciprocated by a suitable mechanism 55. The member 54 is arranged to engage a truck 6 and move it endwise on the track 7 and this truck moves those in front of it, the trucks being moved in this manner at predetermined intervals, a loaded truck being placed in line at the entrance prior to each operation of the thrust member. The trucks at the discharge end are rolled onto a transfer truck and unloaded and again brought into position at the entrance and loaded.

Furthermore, it will be noted that by inclining the side walls 9 of the heating chamber and the resistance rods, they may and preferably do extend downwardly beyond the supports 5 and also below and within their lateral, overhanging or cantilever portions. This insures the application of heat below the supports 5 and between the legs 5a thereof, so that a large volume of heated air and radiant heat may pass around the ware; it also insures the application of heat to the supports 5 so that the latter absorb heat which is conducted to the ware.

The heating means may consist of any desired number of heating elements and the current supply may be regulated to provide any desired temperature in the chamber 2. In the arrangement shown I prefer to subject the ware to a temperature approximating 1500 degrees F. The ware to be treated may be formed of ceramic materials, but ware formed of other materials may be passed through the kiln for treatment.

To those skilled in the art to which my invention relates, many changes in construction and widely diflering embodiments and appli cations of my invention will suggest themselves without departing from the spirit and scope thereof. My disclosures and the descriptions herein are purely-illustrative and are not intended to be in any sense limiting.

What I claim is:

1. In apparatus of the class described, the combination of a preliminary heating chamber, av main heating chamber connected in end to end relation with said preliminary heating chamber to form a continuous kiln, the side walls of said main heating chamber converging downwardly and spaced at their lower ends to form an opening in line with an opening formed in the lower portion of said preliminary heating chamber, conveying means having portions extending upwardly through the openings in said chambers and movable therethrough and carrying ware supports within said chambers, said conveying portions extending upwardly so as to carry said supports in spaced relation to the lower ends of said converging walls, and electric heating units disposed upon one of said converging walls of said main heating chamber and extending to a point below and inwardly of the lateral side portions of said ware supports. Y

2. In apparatus of the class described, the combination of a preliminary heating chamber, a. main heating chamber, the side walls of said main heating chamber converging downwardly and spaced at their lower ends to form an opening in line with an opening formed in the lower portion of said preliminary heating chamber, conveying means below said chambers and having portions extending upwardly through said openings and movable from end to end thereof, ware supports carried by the upper ends of said conveying portions and having lateral portions disposed in spaced relation to and overhangmg the lower ends of said converging walls, and heating means adjacent one of said converging walls and arranged to supply heat above and below said ware supports.

3. In apparatus of the class described, the combination of a preliminary heating chamber, a main heating chamber, the side walls of said main heating chamber converging downwardly and spaced at their lower ends toform an opening in line with an opening formed in the lower portion of said preliminary heating chamber, conveying means I below said chambers and having portions extending upwardly through said openings and movable from end to end thereof, ware supports carried by theupper ends of said conveying portions and having lateral portions '10 disposed in spaced relation to and overhang ing the lower ends of said converging walls, and heating means adjacent one of said converging walls, said heating means comprising electrical heating units disposed in spaced relation-to said converging wall and extending from a point above to a point below the ware supports. H V

" 4. In apparatus of the class described, the

combination or" a preliminary heating chambar, a-main'heating-chamber, the side walls of said main heating chamber converging downwardly and spaced at their lower ends toform an opening in line with an opening 7 formed in the lower portion of said preliminary heating chamber and connected at their upper ends by an arch roof, conveying means below said chambers and having portions extending upwardly through said openings and movable from end to end thereof, ware sup- 0 ports carried by the upper ends of said conveying'portions and having lateral portions disposed in spaced relation to and overhang- 7 ing the lower ends of said -converging walls,

,7 and'heating means adjacent one of said converging walls and arranged to supply heat above and below said ware supports, said heating means comprising electrical heating units disposed in spaced relation to one of said convergingwalls and extending in ver- 40 tical planes from the roof to a point below the adjacent lateral portions of said ware supports,

In testimony whereof, I have hereunto signed my name.

I "HARRY M. ROBERTSON. 

